Percentage Increase Calculator

This measures change rather than proportion. Enter an original value and a new one and it returns the percent increase or decrease, the difference and what the new value is as a percent of the old. A second mode applies a percent change to a number and shows the multiplier behind it, and a third works backwards from a value that has already changed to the figure it started from. That last one catches a common mistake: taking the same percent back off the new value does not return you to the old one, because the base has moved.